To provide a biological indicator capable of precisely evaluating a sterilization effect of microbes in a room, not only in a room comprising a planar wall face and floor face, but also in a room comprising an irregular interior material such as an interior material on which cracking has occurred, and an evaluation method of a sterilization effect using the biological indicator.SOLUTION: There are provided a biological indicator comprising: a hard base material comprising a groove having a width of 1 μm to 100 μm and a depth of 10 μm to 150 μm； and a spore existing in at least the groove of the hard base material, and an evaluation method of the sterilization processing effect using the biological indicator.SELECTED DRAWING: None【課題】平面状の壁面及び床面を備える室内のみならず、亀裂が発生した内装材などの凹凸を有する内装材を備える室内であっても、室内における微生物の滅菌効果を正確に評価することができるバイオロジカルインジケータ、及びバイオロジカルインジケータを用いた滅菌効果の評価方法を提供する。【解決手段】幅１μｍ～１００μｍ、深さ１０μｍ～１５０μｍの溝を有する硬質基材と、前記硬質基材の少なくとも溝内に存在する芽胞と、を含む、バイオロジカルインジケータ及びバイオロジカルインジケータを用いた滅菌処理効果の評価方法。【選択図】なし
